1.\" $OpenBSD: vmm.4,v 1.10 2024/11/05 15:08:46 mlarkin Exp $ 2.\" 3.\"Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org> 4.\" 5.\"Permission to use, copy, modify, and distribute this software for any 6.\"purpose with or without fee is hereby granted, provided that the above 7.\"copyright notice and this permission notice appear in all copies. 8.\" 9.\"THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\"WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\"MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\"ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\"WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\"ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\"OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: November 5 2024 $ 18.Dt VMM 4 amd64 19.Os 20.Sh NAME 21.Nm vmm 22.Nd virtual machine monitor 23.Sh SYNOPSIS 24.Cd "vmm0 at mainbus0" 25.Pp 26.In machine/vmmvar.h 27.Sh DESCRIPTION 28The 29.Nm 30driver implements a virtual machine monitor (VMM) suitable for executing 31.Em virtual machines 32(VMs). 33A VMM runs on the 34.Em host 35operating system and provides facilities to execute one or more 36VMs, each of which is provided with a suitable complement of 37virtual hardware. 38.Pp 39These VMs run independently of the host, but may interact with 40it as any other machine would (e.g. via network communications or 41other means). 42.Pp 43VMs are allocated hardware resources by the VMM during creation, 44including: 45.Pp 46.Bl -bullet -offset indent -compact 47.It 48Virtual CPUs 49.It 50Virtual network interfaces 51.It 52Virtual disk images 53.It 54Virtual serial ports 55.El 56.Pp 57Although VMs execute independently of each other and the host, they 58do consume host resources and, as such, the number of VMs (and their 59configurations) should be taken into consideration when planning 60host capacity. 61.Pp 62The 63.Nm 64driver requires suitable host CPU capabilities in order to provide 65VM services. 66The 67.Nm 68driver requires at least one CPU with hardware-assisted virtualization 69capabilities and nested or extended paging capabilities to be 70present on the host. 71For more information, consult the CPU vendor's documentation. 72.Pp 73The following 74.Xr ioctl 2 75commands are provided for managing 76.Nm 77guests: 78.Bl -tag -width Ds -offset indent 79.It Dv VMM_IOC_CREATE Fa "struct vm_create_params *" 80Create a VM, initializing 81.Nm 82if not yet started. 83(Does not start the VCPU.) 84.It Dv VMM_IOC_RUN Fa "struct vm_run_params *" 85Run a VCPU for a defined VM. 86Return on VM-exit, when the VCPU stopped, or an error occurred. 87.It Dv VMM_IOC_INFO Fa "struct vm_info_params *" 88Get information about the VMs currently hosted by 89.Nm . 90.It Dv VMM_IOC_TERM Fa "struct vm_terminate_params *" 91Terminate a given VM. 92.It Dv VMM_IOC_RESETCPU Fa "struct vm_resetcpu_params *" 93Reset a VCPU to power-on-init state using the provided register state. 94.It Dv VMM_IOC_INTR Fa "struct vm_intr_params *" 95Signal a pending interrupt for a VCPU. 96.It Dv VMM_IOC_READREGS Fa "struct vm_rwregs_params *" 97Read registers of a VCPU. 98.It Dv VMM_IOC_WRITEREGS Fa "struct vm_rwregs_params *" 99Write register values of a VCPU. 100.It Dv VMM_IOC_READVMPARAMS Fa "struct vm_rwvmparams_params *" 101Read paravirtualized hardware parameters (such as 102.Xr pvclock 4 103version) for a VM. 104.It Dv VMM_IOC_WRITEVMPARAMS Fa "struct vm_rwvmparams_params *" 105Write paravirtualized hardware parameters (such as 106.Xr pvclock 4 107guest physical address) for a VM. 108.El 109.Sh SEE ALSO 110.Xr cpu 4 , 111.Xr intro 4 , 112.Xr virtio 4 , 113.Xr vmctl 8 , 114.Xr vmd 8 115.Sh HISTORY 116The 117.Nm 118driver 119appeared in 120.Ox 5.9 . 121.Sh AUTHORS 122.An Mike Larkin Aq Mt mlarkin@openbsd.org 123